Nobody has ever said grows don't differ, conditions don't differ, but to preach a 2 to 5 year skill with growers not understanding there lights. Heck some of them can't figure out how to water. Yeah know when I started the postmaster would throw away your hightimes. There was no net,,, no books easy to get your hands on. There were a few groups around the country and a few mail groups and those names and addresses changed all the time,,, the postmaster once again. To get any help from a master grower was by invitation only. You HAD to be vetted! And nobody has ever said a meter is necessary! Heck when I started we didn't have ph meters. People were using fish tank and swimming pool reagents/kits if they even believed in ph. And those test kits are wildly inaccurate. I remember getting my first ph and tds meter. Cost a $1k for the pair. And I back doored them through a boiler supply house. I worked a third job to buy that pair and saved like a wild man for a year. We learned to grow for the most part outdoor and ran a awful risk of getting busted. And a so so light back then cost as much as a top tier light cost now and was not near as good and more times then not your were buying out of Europe and adapting. I'm all for the tech and skillset. Tech has always cost and there is no true replacement for good tools. And I for one will not go backwards concerning the tech and it's use. I'm the 61 year old cat thats had the Hemi Cuda's and Chargers. I'd much rather have a Focus RS now days. :)